I recently bought a new iMac. I transferred all my iPhoto images over to the new Photos app on my new machine and when I open my Photos app, all my pictures are there. When I try to access these pictures from other apps, such as trying to change my desktop picture to a photo from the app, all the folders in the system preferences Photos folders are empty. Even when I manually navigate to where they are stored on my system, the folders are empty. In other words, the only way I can access the pictures is through the Photos app. What am I doing wrong?